|1.||the Megaman effect|
When a game company lucks out with smash hit game, and then proceeds to crank out worthless clones of the game, cleverly disguising them as "sequels." A prime example is CapCom's MegaMan BattleNetwork series for Game Boy Advance, which began as a launch title for the handheld in 2001, but quickly became an incredibly long "series" of games that are all essentially the same game. Of course, the same thing could be applied to Nintendo and Game Freak's popular Pokemon series for Game Boy, GBA, and the DS.
Dude, WW2 games, Vietnam war games, and Atlus RPGs are suffering from the MegaMan effect.